The present invention relates to a tray used in case-ready packaging that has an optimized geometry. More particularly, the present invention relates to a tray for use in packaging case-ready meat products, wherein the tray has improved sidewall stiffness, particularly resisting horizontal stress, without increasing overall outside dimensions or substantially decreasing overall internal volume.
Historically, fresh meat products available to consumers have been substantially prepared for end-use at the site of final sale. For example, in the area of beef products, unfinished slabs, or portions of slabs, of beef are delivered refrigerated to a retail grocer or butcher where particular cuts of beef are prepared for final sale. This has generally provided a sense of assurance to a customer that the meat product being purchased is of the freshest possible quality. Advances in packing technology and increased consumer demand, however, have led to an increase in the volume of case-ready meat products available to consumers.
Case-ready meat can be generally defined as fresh meat that is prepackaged and/or prelabeled at a centralized location and delivered to the retail market prepared for final sale. According to a 2002 study by Cryovac and the National Cattleman's Beef Association, more than half of the ground beef and more than 80% of the turkey and chicken products delivered to U.S. domestic supermarkets for retail sale are delivered in case-ready packaging. For many supermarkets, especially so-called “mega grocery stores,” case-ready meat products provide not only cost savings in terms of minimizing on-site butchering and packaging, but also increased sanitation and decreased incidence of product spoilage.
To meet the increasing demand for case-ready meat products, many meat producers have moved to specified weight and/or volume packaging of common meat products, such as chicken breast and ground beef. Accordingly, there is an increasing need for packaging supplies for products of predetermined size and volume, particularly packaging trays.
Trays for use in case-ready meat packaging must meet various specifications. In terms of product quality management, trays must be of a standard size that provides a sufficient internal volume to contain the specified weight or volume of meat product and also a specified volume of gases, such as oxygen and carbon dioxide, to provide a desirable gas to product volume ratio. Such gases in precise amounts are used to preserve freshness of the meat product during shipping, to prolong shelf life at the retail site, and to improve product appearance. In particular, oxygen is used to impart the familiar red color to beef products that consumers generally associate with freshness and thus find desirable.
While it is beneficial to have sufficient internal volume, excess volume is undesirable as it correlates to increased outer dimensions that negatively impact shipping costs and lead to reduced availability of shelf space. Tray size needs to be minimized so that the desired weight or volume of meat product can be shipped with as many trays per shipping carton as possible. Unnecessarily large tray size, therefore, increases shipping costs. Further, unnecessarily large tray size reduces the number of packages that can be displayed in a given display case at the retail site.
Tray strength is also a concern for case-ready products. Trays filled with a meat product are often shipped stacked several trays high. Thus, a tray must be resistant to buckling under a vertical load. Further, a tray for case-ready meat products must be resistant to horizontal pressure, such as that imparted by the film overwrap often used to cover the open top of the tray. Generally, the film is stretched across the top of the tray and sealed around the upper edges of the tray.
Minimizing tray dimensions and maximizing tray strength tend to be mutually exclusive goals. For example, one approach to minimizing tray dimensions, thus reducing shipping costs and increasing shelf space, is to reduce the width of the flange that is typically provided on the upper edge of trays. However, experience has shown that if flange width is appreciably decreased, the final packaging can be excessively distorted by the tension of the overwrap film deflecting the sidewalls of the tray inward, making the package appearance unacceptable, or leading to tray integrity failure. Alternatively, increasing flange width can increase resistance of the final package to sidewall deflection, but such added strength comes at the cost of increased external package dimensions, increasing shipping costs and reducing available shelf space.
Accordingly, there remains a need in the art for a tray for case-ready meat products having an optimized geometry. Such an optimized geometry would ideally enable production of a tray of a standardized size with maximized resistance of the tray to vertical and horizontal stress without increased external dimensions. Further, such a tray would maintain the necessary internal volume for containing both a meat product and a necessary amount of beneficial gasses. A tray meeting these criteria is provided by the present invention.